This invention relates to electronic thermometers, particularly those which utilize temperature sensitive probes and probe covers.
Electronic thermometers have been widely used for quick and accurate measurements of body temperature. A temperature sensing probe is inserted orally, rectally, or in an axillary (under the arm) position to measure a patient""s temperature. The temperature sensitive probe is connected to the thermal circuitry in a temperature calculating unit by an electrical cable. The temperature sensitive probe generates a signal. This signal passes through the electrical cable to the temperature calculating unit, where the signal is converted into an equivalent temperature reading. The temperature calculating unit has a digital display which shows the calculated temperature reading.
Before each measurement, a disposable plastic probe cover is placed over the probe. The probe cover is then disposed after each temperature reading and a new probe cover is used for each subsequent measurement. When not in use, the temperature sensitive probe is stored in a housing, well, or recess associated with the temperature calculating unit to minimize probe damage and probe contamination.
Prior art electronic thermometers are susceptible to at least three major sources of contamination in typical use. First, these thermometers employ the same temperature sensitive probes for oral, rectal, and axillary temperature measurements. Even though disposable plastic probe covers are used for each measurement, cross-contamination may still result from use of the same probe. Therefore, rectal or axillary contaminants on the probe may be passed orally to the same patient, or other patients.
The second source of contamination involves the probe storage chamber. Probes are stored in a single housing recess connected to the temperature calculating unit. This recess, once contaminated, may spread contamination to other probes as they may be interchangeably stored in the same recess. Over time the storage chamber may also collect debris and contamination from the storage of multiple probes. So again, contaminants on the probe from rectal or axillary use may be passed orally to the same patient, or other patients.
The third source of contamination relates to the disposable probe covers. Each time a patient""s temperature is measured, the probe is inserted into a box of unused disposable probe covers. The probes of the prior art share a common source of probe covers, so different probes are repeatedly inserted into the same carton. The probe, then, once contaminated, may spread contamination to other unused probe covers. Contaminants deposited on the unused probe cover may then be passed on to the same patient, or other patients.
Since electronic thermometers are used for oral, axillary, and rectal temperature measurements, universal color codes have been adopted by hospitals, using red probes for rectal temperature measurements and blue probes for oral and axillary temperature measurements. This color coding system makes it very easy for the healthcare practitioner to use the proper probe for each temperature reading, reducing the potential for cross-contamination.
The use of a blue probe for oral and axillary temperature measurements and a red probe for rectal temperature measurements reduces the first source of contamination. Separating probe use in this manner also improves patient perception issues related to the health practitioner using the same probe for all types of temperature measurements. Such practice, however, requires two thermometer units to be available at each location if the probes are not interchangeable. Maintaining two units at each location has been considered an inefficient and costly measure. Such a practice also makes the practitioner susceptible to using the most convenient, yet inappropriate, unit.
Some have developed thermometers with detachable probe units. U.S. Pat. No. 4,008,614, assigned to Johnson and Johnson, New Brunswick, N.J., discloses an electronic thermometer unit usable with an oral temperature probe permanently attached to an oral isolation chamber. Similarly, there is a rectal probe permanently attached to a rectal isolation chamber. Connecting the probe and isolation chamber together as one unit thus precludes the inadvertent use of a probe with the wrong isolation chamber.
Similarly, U.S. Pat. No. 4,619,271, assigned to Cheesebrough-Pond""s, Inc., discloses an independent replaceable probe unit including a probe member and a probe chamber for holding the probe member, which can be easily removed and replaced together as a unit. The probe, cable, and isolation chamber are all the same color. The permanent connection assures that the health practitioner stores the probe in the proper isolation chamber, thus reducing the risk of contamination leading to infection. A significant limitation of each of these approaches is that even though the probe is permanently attached to an isolation chamber, both the oral and rectal probe units will be repeatedly and interchangeably inserted into the same box or boxes of probe covers, still exposing the probe to possible contamination.
U.S. Pat. No. 4,572,365, assigned to Cheesebrough-Pond""s Inc., discloses an improved probe cover holding and dispensing arrangement, the objective of which is to provide convenient access to clean probe covers. An electronic thermometer housing contains a chamber for receiving a carton of probe covers. Once the carton is inserted and secured within the housing, an aperture in the thermometer housing, normally closed by a sliding cover, provides access to the inserted carton of probe covers. Still, in this arrangement, the probe and isolation unit may be interchanged between oral and rectal without changing the cartridge of probe covers. Both oral and rectal probe units share access to the same source of probe covers, providing a source of cross-contamination.
U.S. Pat. No. 4,260,058 to Seymour et al. discloses an arrangement of mounting a holder on top of the thermometer device to receive a cartridge of probe covers. However, in this approach, probe covers are still stored with the temperature calculating unit. The disclosed arrangement does not require a dedicated probe and isolation chamber. This again may allow both oral and rectal probes access to a shared source of probe covers, providing a source of contamination.
Each of these prior art approaches fails to address the exposure to contamination as each temperature sensitive probe, oral or rectal, is repeatedly inserted into the same box or boxes of probe covers. In each approach, the same source of probe covers is used whether the covers are stored in connection with the temperature calculating unit or separate from the thermometer altogether.
Currently there is a need for an electronic thermometer which reduces patient exposure to all sources of cross-contamination, aids in infection control, and provides a clean, uncontaminated, readily accessible source of probe covers.
It is therefore an object of this invention to provide a thermometer that reduces all three major sources of contamination and cross-contamination by eliminating the use of the same probe for oral, axillary, and rectal temperature measurements, the use of the same storage chamber for each type of probe, and the use of the same supply of probe covers for each type of probe.
It is another object of this invention to provide a removable module capable of receiving and storing both a temperature sensitive probe and a clean, uncontaminated supply of disposable probe covers.
It is a further object of this invention to provide a removable module with an isolation chamber that prevents the storage of a temperature sensitive probe with a probe cover remaining on the probe.
It is yet another object of this invention to provide a removable module that allows the practitioner to readily view a supply of probe covers through a transparent module housing without disassembling or physically contacting the removable module.
It is still another object of this invention to provide a module housing which aids in infection control by being easily cleaned or inexpensively replaced.
The present invention reduces the risk of a patient""s exposure to all of the common sources of contamination encountered in the use of electronic thermometers. The minimization in risk is accomplished by isolating the storage of the temperature sensitive probe and the disposable probe covers used for oral, axillary, and rectal temperature measurements into dedicated units, or modules.
This invention features at least two types of removable modules interchangeably operable with one temperature calculating unit. The removable module is comprised of a probe assembly and a module housing. The module housing includes two chambers, one to store the probe and one to store a fresh supply of probe covers. Each of the module housing and probe assembly are color coded according to the standard convention of red for rectal measurements and blue for oral and axillary measurements.
In the described embodiment, a red probe assembly is attached to a red module housing, the housing containing an isolation chamber to store the temperature sensitive probe and a storage chamber to store a supply of disposable probe covers. Similarly, a blue probe assembly is attached to a blue module housing, the housing containing an isolation chamber to store the temperature sensitive probe and a storage chamber to store a supply of disposable probe covers. The removable module requires that the rectal probe, with the supply of probe covers, is used only with the rectal probe. These dedicated modules prevent the commingling of the probe, the isolation chamber, and the probe cover supply during temperature measurement, thus minimizing thermometer contamination.
Another feature of the present invention is that the module housing may be made of a translucent or transparent material. The transparent, or partially transparent, housing allows the healthcare practitioner to conveniently view the remaining supply of probe covers at any given time. The carton of disposable probe covers described in the preferred embodiment has a tear away top and/or side panels. When these cartons are used together with the transparent or partially transparent removable module, the healthcare practitioner can view and count the remaining probe covers through the module housing. This improved design provides an easily viewable arrangement that helps avoid the necessity to physically contact the housing or probe covers in order to check the remaining supply.
These and additional features and advantages of the invention disclosed here will be further understood from the following detailed disclosure of the preferred embodiment.